Our holiday to Turkey (in 12 days

) with First Choice has gone
up by £1600 since I booked it in the first edition brochure last May

But I know for a fact that the holiday we've booked for Ibiza next August with Thomsons will go down by next July - it always does for that particular hotel every year. It's swings and roundabouts and I got the morning flights I wanted, and the satisfaction of knowing it's all sorted. It's not just holidays, it happens with everything, I bought my daughter an expensive pair of jeans in River Island last month, she hasn't even worn them yet and now they're in the sale at £9.99 - that's life. I get enough bargains along the way to make up for the reductions-after-purchase disappointment.
Now if your holiday had gone down by a considerable amount and you had only paid your deposit up to now, it might be worth cancelling and losing your deposit and then re-booking and still making a saving, but the reduction would have to be considerably more than the deposit you've already paid to make it worth your while faffing around.